The space environment was very raging in the days before the great blackout that plunged thousands of Tenerife in the dark on September 29. Two days earlier, the Sun ejected a “jet of protons” towards Earth through what is called the solar coronal hole, a dark area of the star where the solar wind acquires a lot of speed. That rapid ejection of mass accompanied by a high density is what caused the Earth’s magnetic field to “compress” and vibrate without stopping until it touched the surface.
With the data collected by a group of researchers from the University of Alcalá – led by the head of the National Space Meteorology Service, Consuelo Cid – that vibration was especially intense in Tenerife. Far from being a simple coincidence, this unusual circumstance is beginning to be considered as a possible cause of the origin of energy zero. And, so far, it is the only response to the situation that left the population of the Island in the dark for nine hours.
This is stated by an investigation, advanced by the El País newspaper and presented at the European Space Weather Week Congress. Titled The space weather environment before the Tenerife blackout, the study chronicles the situation in which the space environment was in the days before the blackout. To carry out this study, the researchers collected data from different solar and magnetic scanning instruments and then crossed them.
Among them, researchers from the University of Alcalá made use of the measurements of the Earth’s magnetic field at the surface level of the Güímar station, as well as observations by several satellites (GOES-14 and 15 of NOAA and ACE of NASA ) that examine the space environment and monitor the flow of energy particles near the Earth.
These days, there was a “geomagnetic disturbance,” explains Cid. Basically, the magnetosphere had touched down due to a very powerful and unusual solar activity, an “interplanetary shock” that caused it to flatten and generate what is known as a geomagnetic storm. It is not common for these vibrations to occur at latitudes as low as the one in the Canary Islands.
In fact, the northern lights that are more common at the planet’s poles are caused by fluctuations in the magnetic field that protects the Earth. However, that it happens near the equator is not strange either. “It is not the first time that a vibration of the magnetosphere is recorded in these latitudes,” says the researcher, who insists that there are “aligned currents” in these areas. “They are not as relevant as the auroral currents, but they may also be affected by these phenomena temporarily,” explains Cid.
To get to the Islands, the ejection of particles, in turn, had to have left the inner zone of the star, specifically in the solar equator. He did so, through a solar coronal hole located in the west of the Sun. This was perceived in the photographic records of the SDO satellite of NASA, which shows a large black spot just in that place of the Sun. “Usually this solar activity it is usually located at the poles of the star, which is ejected up or down, “explains the researcher at the Canary Islands Institute of Astrophysics (IAC), Héctor Socas.
However, being in that unique location, it coincided directly with the orbit in which the planets are rotating. “All the coronal holes that are more or less near the center of the solar disk will reach us here in the Canary Islands,” says the researcher. Then it was only necessary to blow the solar magnetic wind near the coronal hole so that a “high velocity particle jet” would abandon the solar heat and fully touch the Earth.
After this first burst of protons with a high density and speed – and with the magnetic layer that surrounds the Earth completely compressed – the solar wind continued to emanate from the Sun with different intensities the following days. This phenomenon caused the magnetic layer to continue vibrating continuously for the next two days (September 28 and 29).
These oscillations so close to the earth’s surface are usually related, as the researchers explain, to breakdowns in induced currents that affect terrestrial energy transformers and, consequently, cause failures in electrical networks. Despite the possible causal relationship between the phenomenon and the energy zero of Tenerife, the scientist is cautious. In fact, the results are preliminary and therefore they are working hard to analyze more data from other instruments.
“We are not experts and we do not know for sure if this was the cause of the blackout,” Cid insists, indicating that “it may be a cause.” “The population has not been given any explanation and on the other hand, what we see in the data is that the situation in our space environment was anomalous. It was not an extreme event in terms of its intensity but it was very prolonged in the time, “he concludes. The only thing that has been proven is that it was a very fast solar wind that caused these changes in the magnetosphere and disturbed the space.